ANCHORAGE (AP) -- Along most of the outer coast of the Kenai Peninsula, in Kenai Fjords National Park, mountains and cliffs plunge straight down into the green waters of the Gulf of Alaska.

But here and there, mostly inside bays like this glacier-fed inlet, lie narrow strips of beaches and lush lowlands. Black bears love these places because grasses, berries and sometimes salmon are abundant. Increasingly, park visitors love these places, too, because they offer rare flat ground on which to pitch a tent, fish or get off a boat to explore.

For the first time ever, bear researchers are studying black bears inside Kenai Fjords park. One of the main questions they hope to answer is whether human use of these beaches has affected black bears.

''It looks like some of these places that make good campsites made good bear habitat, too,'' said Jeff Villepique, the University of Alaska Fairbanks graduate student who is leading a three-year bear study. ''We want to know if bears do different things when there are humans there. Do they avoid or go to those areas?''

Villepique also plans to do some genetic testing using follicles from the hairs of black bears to determine whether the park's bears are distinct genetically from other Kenai bears, isolated perhaps by an ice-crusted mountain spine that blocks the coast from the rest of the peninsula.

The park's coastal black bears might even prove to be some sort of remnant population, more closely related to Southeast Alaska bears than those from the rest of the Kenai Peninsula or Southcentral Alaska.

Pilots have occasionally spotted bear tracks crossing the glaciers, Villepique said, which is at least a six-mile trek. In recent years brown bears have occasionally been spotted along the coast, suggesting that at least some bears may have crossed the ice fields.

But the short-term question the park is most interested in is how bears are affected by visitors. To answer it, Villepique and research assistant Phil Joy, also from UAF, are comparing black bears that live in two bays -- Aialik Bay, which gets more visitors, and the remote Paguna Arm of Two Arm Bay, which gets few.

The park is interested because visitation has grown by more than 10 percent a year recently. Almost 300,000 came to the park last year according to superintendent Anne Castellina. The largest share went either to the visitor center or to the road-accessible Exit Glacier near Seward. But about 6,300 were kayakers, fishermen and other backcountry visitors, and another 93,000 people went out on tour boats.

Beautiful bays like Aialik, which used to be considered remote and were visited only by the most intrepid, now get a steady stream of boaters each summer, said chief ranger Peter Fitzmaurice.

Human-bear conflicts aren't yet a big problem in Kenai Fjords, but between 1983 and 1994, the park has had nine reports of bears shot by humans in defense of life and property, Fitzmaurice said.

A bear was shot in May in McMullen Bay. Park rangers found the bear's carcass but not the person who shot it.

If the biologists can determine which areas are most important to the bears, then the park may be able to steer visitors away, Fitzmaurice said. Or visitors could be better educated to avoid conflicts, Castellina said.

''I don't want to have to call someone's mom to say they were hurt by a bear,'' Castellina said. ''I don't want to have to shoot a bear, either.''

The biologists see bears all the time on the beaches and up on the mountainsides. So far this summer, Villepique and Joy have trapped and radio-collared six bears. The collars are fitted with a radio-telemetry device, which sends out a signal that can be picked up with an antenna and tracking equipment, and also with a global positioning system.

Every two hours, the GPS device searches for three or more satellites to fix its position.

If a connection is made with the satellites, the bear's position is recorded inside the collar. The result is a detailed record of the bear's movements, which biologists plan to eventually match with daily surveys of where people are camping.

The biologists hope to collar nine more bears this summer. In September, they will release a radio signal that sets off a small explosive inside each collar to break them off the bears' necks. Then comes the difficult part: Villepique and Joy will need to retrieve the collars.

''We know the bears go some very steep places,'' Villepique said. ''We realized early on that we'll need ropes and climbing gear to get them back. But if the bear is on top of a cliff, we won't blow off the collar.''

Beginning next summer, the biologists also plan to snag bear hair with barbed-wire corrals. By examining the DNA contained in the hair follicles, the researchers hope to identify individual bears and thereby get a population estimate for the two bays. The tests should also be able to determine how connected the bears are to other bears in Alaska and North America.

Trapping bears for radio collaring is not easy. The biologists must shuttle six long barrel traps between beaches. Each trap is made of three 55-gallon drums welded together with a trap door on the front. They carry the contraptions up the beach, then hang a bag of dog food doused with a strawberry-scented bear lure inside.

After all that, trapping a bear is no sure thing. ''They're wary of traps,'' Villepique said.

Typically, Villepique said, they check the traps physically twice a day, survey the bay for visitors and spend most of the rest of the time doing vegetation surveys to see what's available for bears to eat. Earlier in the summer, the bears ate such vegetation as goose tongue, rye grass and lupine roots. Later in the summer, the researchers predicted, the bears would prefer berries and fish.

Whenever they happen to capture a bear, they tranquilize it and then work quickly to extract as much data as possible. They weigh and measure the animal, tattoo an identification number inside its lip, take a blood sample to determine its health and for genetic material, and sample hair and claw shavings small slivers extracted with a fine drill.

From the claw samples, the biologists will be able to say whether the bear's food is coming mainly from marine or land sources.

And although it isn't part of the study, the bear researchers are hoping this summer to shake up their routine by catching a glimpse of a legendary park bear, or possibly even capturing and collaring it. Known as the ''big-eared bear,'' the black bear is reputed to have ears as large as pingpong paddles and has been seen independently by a boat captain and by one of the park's rangers, Joy said. Even more mysterious, the bear once had two cubs.

One had big ears, and the other did not.

''I asked if I would know the big-eared bear if I saw it,'' Joy said. ''I was told it's like seeing King Kong. If you saw King Kong, you wouldn't wonder if it was a chimpanzee.''